Variable displacement compressor

Abstract

A variable displacement compressor includes a rotor, which is fixed to a drive shaft, and a pivotal swash plate, which is supported on the drive shaft and slides in an axial direction along the drive shaft. A hinge mechanism is located between the rotor and the swash plate. The hinge mechanism rotates the swash plate integrally with the rotor and guides the pivoting and the sliding motion of the swash plate. The hinge mechanism includes a swing arm, which extends from the swash plate. The swash plate is made of aluminum or aluminum alloy material. The swing arm is separate from the swash plate and is made of iron-based metal material. Therefore, while the swash plate is light, the hinge mechanism is strong.

What is claimed is:  
     
       1. A variable displacement compressor comprising: 
       a housing defining a cylinder bore;  
       a piston located in the cylinder bore;  
       a drive shaft rotatably supported by the housing;  
       a rotor mounted on the drive shaft to rotate integrally with the drive shaft;  
       a drive plate having at least a portion of aluminum or aluminum alloy material, wherein the drive plate is connected to the piston to convert rotation of the drive shaft to reciprocation of the piston and the aluminum or aluminum alloy portion of the drive plate is connected to the drive shaft such that the drive plate inclines and slides axially along the drive shaft, varying the piston stroke to change the displacement of the compressor; and  
       a hinge mechanism located between the rotor and the drive plate for rotating the drive plate integrally with the rotor and for guiding the motion of the drive plate, the hinge mechanism comprising a first hinge part made of iron-based metal material, the first hinge part being connected to the aluminum or aluminum alloy portion of the drive plate, and a second hinge part extending from the rotor, wherein the first and second hinge parts are coupled to one another to permit both pivoting and sliding motion between the first and second hinge parts.  
     
     
       2. A compressor according to claim  1 , wherein the first hinge part includes a mounting hole, a pin is pressed fitted into the mounting hole, and one end of the pin extends from the first hinge part and is received in a guide opening of the second hinge part. 
     
     
       3. A compressor according to claim  1 , wherein the second hinge part includes a pair of support arms, and the first hinge part is held between the support arms. 
     
     
       4. A compressor according to claim  3 , wherein the first hinge part includes a mounting hole, a pin is pressed fitted into the mounting hole, and the ends of the pin extend from the first hinge part and are received by the support arms. 
     
     
       5. A compressor according to claim  1 , wherein hard particles of silicon are embedded in the drive plate. 
     
     
       6. A compressor according to claim  5 , wherein a content of the hard particles is more than 12 wt % by weight of the material of the drive plate. 
     
     
       7. A compressor according to claim  5 , wherein an average diameter of the hard particles is in a range of 10 to 60 μm. 
     
     
       8. A compressor according to claim  1 , wherein the first hinge part is fixed to the drive plate with a bolt. 
     
     
       9. A compressor according to claim  1 , wherein the first hinge part is fixed to the drive plate by friction welding. 
     
     
       10. A compressor according to claim  1 , wherein the aluminum or aluminum alloy portion of the drive plate includes a through-hole for receiving the drive shaft, the through-hole comprising an engaging section which is part of a wall defining the through-hole, and the engaging section always engages the drive shaft during rotation of the drive plate. 
     
     
       11. A compressor according to claim  1 , further comprising a counter-weight for adjusting the balance of the drive plate, the counter-weight being attached to the drive plate on a side of the drive plate that is opposite to the first hinge part with respect to the axis of the drive shaft, wherein the counter-weight is integrally formed with the first hinge part. 
     
     
       12. A compressor according to claim  11 , wherein the counter-weight engages the rotor when the drive plate reaches its maximum inclination. 
     
     
       13. A variable displacement compressor comprising: 
       a housing defining a cylinder bore;  
       a piston located in the cylinder bore;  
       a drive shaft rotatably supported by the housing;  
       a rotor mounted on the drive shaft to rotate integrally with the drive shaft;  
       a swash plate of an aluminum alloy material, the swash plate being connected to the piston to convert rotation of the drive shaft to reciprocation of the piston, wherein the swash plate is supported on the drive shaft, the swash plate includes a through-hole defined by a wall of the alluminum alloy material that includes an engaging section, the engaging section always engaging the drive shaft during rotation of the swash plate, and the swash plate inclines and slides axially along the drive shaft to vary the piston stroke and change the displacement of the compressor; and  
       a hinge mechanism located between the rotor and the swash plate for rotating the swash plate integrally with the rotor and for guiding the motion of the swash plate, the hinge mechanism comprising a first hinge part connected to the aluminum alloy material of the swash plate, a second hinge part extending from the rotor, and a pin attached to the first hinge part and having an end extending from the first hinge part to the second hinge part, wherein the first hinge part is made of an iron-based metal material and includes a mounting hole in which the pin is press fitted, and the second hinge part includes a guide hole for receiving the end of the pin to guide movement of the first hinge part relative to the second hinge part.  
     
     
       14. A compressor according to claim  13 , wherein the second hinge part includes two support arms between which the first hinge part is held, and the pin extends from the first hinge part to each support arm. 
     
     
       15. A compressor according to claim  13 , further comprising hard particles of silicon embedded in the swash plate. 
     
     
       16. A compressor according to claim  15 , wherein a content of the hard particles is more than 12 wt %. 
     
     
       17. A compressor according to claim  15 , wherein an average diameter of the hard particles is in a range of 10 to 60 μm. 
     
     
       18. A compressor according to claim  13 , wherein the first hinge part is fixed to the swash plate with a bolt. 
     
     
       19. A compressor according to claim  13 , wherein the compressor further comprises a counter-weight for adjusting the balance of the swash plate, wherein the counter-weight is attached to the swash plate on a side of the swash plate that is opposite to the first hinge part with respect to the axis of the drive shaft, and wherein the counter-weight is integrally formed with the first hinge part. 
     
     
       20. A compressor according to claim  19 , wherein the counter-weight engages the rotor when the swash plate reaches its maximum inclination.